[tt]You got idea![/tt]
Food containers
So I was crafting some food earlier and I noticed in my inventory:
'S mac & cheese (fresh) (hot) (6)'
...huh. So I'm just carrying hot mac and cheese around in my pockets?
Messy food items like this should require some sort of container ('tupperware', lidded plastic containers) or at least a plate. Things as messy as mac and cheese might even fit in a plastic bottle or jug. Carrying messy food around without a container could ruin electronic/paper/fabric items, and possibly add the Wet morale penalty.
The containers I mentioned above could also help prevent food from spoiling (not completely, but more than just shoving it onto a shelf).
3D Printers
I’ve worked with 3D printers before, and they don’t seem TOO high-tech; I suspect they’d be pretty useful for the scientists pre-cataclysm. 3D printers in C:DDA could be used to either A: relatively quickly produce small plastic items that would take a long time to shape manually or B: slowly produce complicated plastic items that would otherwise be impossible.
There should probably be several different models or tiers: low tier printers should have a chance to mess up while making an item or break occasionally (due to poorly-made parts and software), confer a ‘fragile’ status on items they make (this could depend on quality of plastic instead), and generally be incapable of making very complicated things - but they have the potential to be incredibly small and lightweight (i.e. can be (barely) carried in one hand and battery-operated, although it might gobble up batteries like nobody’s business). As printer models become heavier and more solidly built, they become more reliable and accurate - this could progress to vehicle-mounted printers, then small 1-tile devices found in high-end electronics stores or possibly Public Works, then gigantic multitile printers found in labs (these might even be capable of ‘printing’ metal, considering the way recent IRL research is going).
To actually use a 3D printer, a survivor would need to find model files (on USB drives or SD cards?) of items and spools of plastic wire. Both of these could probably be found in electronics stores, the former only in the ‘prettier’ ones. As stated above, plastic might also have a quality - lower quality plastic would make incredibly fragile items, but be much easier to find.
The skills required to operate one would probably either involve sheer survivability (for finding USB drives buried under zillions of zombies); or Computers for operating CAD software and data transfer, Fabrication/Mechanics for creating models for the printer to use, and definitely Mechanics/Electronics for repairing/calibrating the lower-end ones. At high Mechanics and Electronics skill, a survivor might be able to craft a simpler 3D printer with a soldering iron, rubber tubes, some electric motors, a sheet of glass, a hotplate, some electronic parts (enough for a PDA) and plastic chunks, some pipes and a whole buncha tools.
Vehicle Heating
Also, I’ve been browsing this here suggestions board a lot, and thought of a neat combination of two different ideas (fires warming up those nearby and solar panels) - vehicles could have ‘solar heaters’, based off of solar power plants. These would require LOTS of mirrors, which would be hard to collect (considering how smashed up most vehicles with mirrors are when I find them) but worth it during winter. The mirrors would focus sunlight onto a central point - a tube with water flowing through it. This water could then be used to heat the interior of the car, used as a hotplate, or even possibly used to power a heat engine (steam cars!). The problem here is that, like normal solar panels, you need a lot of surface area to get any meaningful result - this could introduce a tradeoff between having solar power and not freezing to death (or having ‘different’ solar power).